Managed C++/CLI

[DllImport(S"Kernel32.dll", EntryPoint="ReadFile", CharSet=CharSet::Auto)]<br />
	extern "C"  Boolean ReadFileNative(IntPtr hFile,StringBuilder *lpBuffer,<br />
	UInt32 nNumberOfBytesToRead,<br />
	UInt32 *lpNumberOfBytesRead, <br />
	Int32);

String *GetFileTextWithImport(String *fileName){<br />
		FileStream *fs=new FileStream(fileName,FileMode::Open);<br />
	//Wrapping a handle with HandleRef guarantees that<br />
		//the managed object is not garbage collected <br />
		//until the platform invoke call completes.<br />
		HandleRef hRef=HandleRef(fs,fs->Handle);<br />
		StringBuilder *sbText=new StringBuilder(fs->Length);<br />
		UInt32 uiToRead=0;<br />
		ReadFileNative(hRef.Handle,sbText,fs->Length,&uiToRead,0);<br />
		fs->Dispose();<br />
		return sbText->ToString();<br />
	}

String *GetFileText(String *fileName){<br />
		FileStream *fs=new FileStream(fileName,FileMode::Open);<br />
		HandleRef hRef=HandleRef(fs,fs->Handle);<br />
		IntPtr ptrText=Marshal::AllocHGlobal(fs->Length);<br />
		DWORD uiToRead=fs->Length, uiRead=0;<br />
		ReadFile((HANDLE)hRef.Handle,ptrText.ToPointer(),uiToRead,&uiRead,NULL);<br />
		String *strRet=Marshal::PtrToStringAnsi(ptrText);<br />
		Marshal::FreeHGlobal(ptrText);<br />
		fs->Dispose();<br />
		return strRet;

#using <mscorlib.dll><br />
using namespace System;<br />
public __delegate Int32 FactorialCallback(Int32,Int32*);<br />
public __gc class Factorial{<br />
public:<br />
FactorialCallback *fc;<br />
Factorial(){<br />
	this->fc=new FactorialCallback(this, GetFactorial);<br />
}<br />
Int32 GetFactorial(Int32 iSeed, Int32 *iNumberOfCircles){<br />
		(*iNumberOfCircles)++;<br />
		return (iSeed==0)?1:(GetFactorial(iSeed-1,iNumberOfCircles)*iSeed);<br />
	}<br />
Void FactorialComplete(IAsyncResult *ar){<br />
	Int32 iNumberOfCircles;<br />
	Int32 iResult=this->fc->EndInvoke(&iNumberOfCircles,ar);<br />
	Console::WriteLine(S"The result is {0}, nuber of circles is {1}",iResult.ToString(),(iNumberOfCircles-1).ToString());<br />
	Console::Read();<br />
}<br />
};<br />
<br />
int _tmain()<br />
{<br />
   Factorial *fact=new Factorial();<br />
   Int32 dummy=0;<br />
   AsyncCallback *ac=new AsyncCallback(fact,&Factorial::FactorialComplete);<br />
   fact->fc->BeginInvoke(5,&dummy,ac,NULL);<br />
   Console::WriteLine(S"Main complete");<br />
   Console::Read();<br />
<br />
	return 0;<br />
}